diff --git a/build_release.sh b/build_release.sh
index 9df0035765050a86773df690c1688f15be394fc4..e0c387455fa3cbabc331917a411413f3f3e88aa9 100755
--- a/build_release.sh
+++ b/build_release.sh
@@ -1,13 +1,11 @@
 #!/bin/sh
 
-set -e
+set -eu
 
 tag="r$(./release_num.sh)"
 rev=$(git log --format=%h -1)
 
 target=$1
 
-# TODO error if $target is empty
-
 echo "$tag.$rev $target"
 $(which time) zig build -Dtarget=$target -Duse-full-name -Dtag=$tag --prefix .